TexasNative

OK. Got my 385 build running and i'm in the process of going back through and checking my work before really starting to break in the motor. The biggest problem i'm seeing is that the timing is WAY retarded. Took a short test drive earlier while logging data and the timing advance on the #1 cylinder never got above -13*. The minimum advance is logged at -42*, max is -13* with an overall average of 29.7* Everything seems to run fairly well but it's obviously lacking severely in the power department. I've seen a few knock sensor counts but when it does detect knock the PCM only pulls about 1-2* max. The tune is from PCM-For-Less and the program takes into consideration a 100 shot of nitrous so I would expect a little bit of retard at WOT but this is pretty extreme. Any ideas?

Sorry: This is a 96 LT1 and some of the mods are as follows:

- All forged bottom end
- Hogged heads
- Hogged intake
- 58mm Holley TB
- 236/242 cam
- MSD Opti
- MSD coil
- MSD 8.5mm wires
- Meziere EWP
- Walbro 255 FP
- Aeromotive adjustable regulator
- Parallel flow fuel rail conversion
- 36lb injectors
- Kooks 1 3/4" LT's
- True duals (no cats)
- All emissions deleted
- Tune by PCM-For-Less

EVERYTHING on this motor is brand new except for the block and intake. This includes all wiring, sensors, nuts/bolts, etc...

moehorsepower

iTrader: (3)

I don't think you are really running that much in the negative, if that were the case, it would be backfiring thru the intake for being so severely retarted in timing. Are you using the correct scanning software? I use Data Master and if I use the wrong version, it will log but give me crazy numbers..

SS RRR

iTrader: (2)

I seem to remember a while ago using LT1 Edit to scan my PCM and it would give me a negative value for total advanced timing. I'm not even sure your engine would run with that much timing pulled out...
I'm wondering if you know for sure the timing sprockets were aligned correctly when installed?

TexasNative

You're both correct. I didn't mean to put negative value above. I was seeing ADVANCED timing not retarded. Turns out I am complete idiot and didn't have the cell where the timing appears expanded far enough and I couldn't see that it was actually BTDC and it was reading just about right. I'm such a freakin' idiot!

Nastyc4

iTrader: (13)

You're an idiot .

Lol

TexasNative

Yep. Sometimes my stupidity just amazes me!

ZFreie

Simple over look, but, do you think its still down on power?

Nastyc4

iTrader: (13)

I couldn't help it it was like being given permission to say that :p

Details on the heads? Chamber vol? Compression? Flow? Cam specs?

TexasNative

Yeah. Seems like it's still somewhat lacking in power. Requested specs are as follows:

- 385 CI
- 50cc chambers
- 2.00"/1.56" valves
- 11.5:1 CR
- Not sure on flow but heads are ported as far as you can open a factory
casting
- Cam is 236/242 @ .050 112 LSA
- 1.6 RR's
- FP is at 45lbs and is consistent during operation

One thing I just noticed on this last drive were P0200 and P1222 codes indicating an intermittent problem with the injector control circuit. I'm going to check my injector harness and injectors to make sure everything is working properly and then take a few more drives, log a little more data under varying conditions and switch between 93 octane and C16 to see what happens. If anybody has any input i'd appreciate it. I'll post what I find in my logs later.

WS Sick

I thought when it gave a negative number like that it meant it was say -13 down from the given value of the program table.

Nastyc4

iTrader: (13)

I have a fuel rail we welded up to get better flow with I'm assuming that's what you have done as well. Make sure the regulator Is in the correct area and not regulating fuel from the pump. The shoppe who built my motor set it up wrong where under wot the injectors were emptying the rails and the regulator wasn't allowing more fuel in. I was leaning out at wot and it was an easy fix.

Check your plugs to make sure they aren't fouled and the correct heat range to be able to pull out heat and still keep themselves clean. What plugs are you running?

What is you maximum advance at wot from 3500 and up?

TexasNative

Yep. That's what I did as well. I removed the stock FPR and crossover tubes and welded up the ends. Added two AN fittings in the back of the rails and two on top up front. Fuel comes from the pump, to a Y-block, into the rails, out of the rails into the FPR and to the return. I made another adjustment to the FPR (raised it by about 1lb) and it seems to have livened things up a little but i'm seeing bank 2 go lean at WOT. A screenshot of some of the logging is below.



Not sure if the lean condition is due to a faulty O2 sensor or if it has something to do with the Injector Control Circuit code i'm seeing. Engine was too hot after the run so i'll pull the plugs tomorrow and see what they look like. Also going to hook up the wideband on that side and see how it looks as well. One last thing I noted is that i'm seeing the oil pressure drop at idle to around 20lbw. When I kick the idle up to about 1200 it rises to around 40lbs and at cruising speed it sits around 60+. Any ideas?

BTW... plugs are Autolite 103 and gapped at 0.050". They looked pretty good yesterday when I checked them.

Log file continued:

gatorhead

iTrader: (4)

I am seeing a problem with an O2 check them to be sure!

TexasNative

Well, the results are in. I tested for continuity and ohmed out all the fuel injector control wires and found that cylinders six and eight were swapped. Then, I swapped out the O2 sensor on bank 2 with the wideband and it seems to have fixed my issues. It's running perfectly! The thing runs like a raped ape now and just rips the tires all the way up through third gear without really going anywhere. That being said i'm afraid to jump on it too much because the only thing in the car that hasn't been replaced or upgraded is the sad old 10 bolt so guess it's time to finish out the project with a solid 12 bolt or 9 inch. Anyhow, thanks for everyone's input here, it helped to have multiple eyes and brains working. Time to go terrorize my neighborhood now.